Piano



C. MEHLIN.

PIANO. APPLICATION men JULY 20, I918.

' Patented Apr. 6, 1920.

M m l a r "m 2\ 91 A rigid frame.

UNITED STATES CHARLES MEI-ILIN, 0F FORT LEE, NEW JERSEY.

Piano.

Specification of Letters Patent.

Patent-ed Apr. 5, 1920.

Application filed July 20, 1918. Serial No. 245,816.

To all whom t may concern:

Be it known that l, CHARLES MnnLIN, a citizen of the United States, residing at Fort Lee, county of Bergen, in the State of New Jersey, have invented certain new and use ful Improvements in Pianos, of which the following is a specification, reference being had to the accpmpanying drawing forming a part hereof.

This invention has relation particularly to the sounding boards of pianos and has for its general object to improve the tone of pianos by securing prolonged vibration with full richness and sonority and a true singing value. To accomplish this result the sounding board is cut oii at one end across the grain of the wood and across the line of the bridge or bridges. whereby the sounding board is to some extentleit tree at one end, so that the vibrations, which follow the grain of the wood. are transmitted freely to the air instead of being deadened through the contact of the sounding board with the It will be understood that the extent to which the sounding board can be thus left free is limited by structural considerations and that the extent of the cutting is the maximum within the limits so imposed. The invention will be more fully explained hereinafter with reference to the accompanying drawing in which it is illus trated, and in which Figure 1 is a top view of a sounding board for a grand piano with its appurtenances and embodying the invention, some of the strings being omitted.

Fig. 2 is a similar view of a sounding board for an upright piano.

So far asthe present invention is concerned the differences in the shape of the sounding board a, and the construction of the string frame I), with its wrest plank and hitch-pins, and bridges c and (Z, are immaterial, save that the bridges 0 and d are substantially parallel with the grain of the wood of the sounding board. The description of the application of the invention to one of the sounding boards shown will, therefore, suffice for a description of the application of the invention to both.

As already stated, the grain of the wood of the sounding board a runs throughout in the same general direction, which is substantially parallel with the general line of the bridges c and (2. At one end of the sounding board, preferably in the line of its greatest length, the sounding board is cut across the grain of the wood, as at c, at some distance within its perimeter and therefore within the line of the inside rim (not shown) to which the sounding board, as usual, is glued all around its perimeter. which is thus formed in the sounding board may be suited in shape to the shape of the board and of its-supports, being shown in Fig. l as substantially segn'lental and in Fig. 2 as triangular. The essential feature is that the board shall be tree at one end in a line substantially at right angles to the grain of the wood and across the line of the bridge or bridges and as long as structural conditions ,will permit, that is, as long as it can be made without weakening the board unduly. The vibrations of the piano strings are communicated through the bridges to the sounding board to which they are attached and travel on or in the sounding board in the direction of the grain of the wood. it the board is tightly fastened to the rim, with no free edge, the vibrations are shortened and deadened and react against other vibrations, impairing the tonal quality which would be produced it these conditions did not exist. \Vhen, however, the sounding board is made free for a substantial distance, across the grain of the Wood, the evil conditions referred. to are avoided and the vibrations, unimpeded, are transmitted directly from the sounding board to the air.

It will be understood that the precise manner in which the sounding board shall be made free at one end will depend, in each instance. upon the structural conditions and that the invention, except as pointed out in the claims, is not limited to the particular constructions shown and described herein.

1 claim as my invention:

in a piano, the combination of a string frame. a bridge and a sounding board supported along its perimeter, the bridge hear ing on the sounding board and the sounding board having its grain substantially parallel with the bridge and having one edge free on a line of substantial length substantially at right angles with the grain and across the line of the bridge.

This specification signed this 27th day of June, AQD. 1918.

' CHARLES Menus,

The opening f 

